Contact assembly locking means



Jan. 13, 1959 J. FILKO 2,868,903

cozmcr ASSEMBLY LOCKING MEANS Filed Oct. 25, 1956 FIG I INVENTOR: JOHN Fl LKO ATT'YS United States Patent CONTACT ASSEMBLY LOCKING MEANS John Filko, Chicago, Ill.

Application October 25, 1956,Serial No. 618,221

2 Claims. (Cl. 200-30) This invention relates, in general, to a contact assembly of the type disclosed in applicants Patent No. 2,727,104 wherein there is shown a contact arm having a contact, and a spring associated with the arm to press the arm toward a second contact which cooperates with the first contact. More specifically, the invention relates to means for securing the free end of the spring to a part of the contact assembly on the base plate.

The invention comprises, in general, a base plate,

which is adapted to be removably mounted on a distributor plate in the manner disclosed in the aforesaid Patent No. 2,727,104. The base plate is provided with an upstanding ear to which an insulation member, in the form of a strip of insulated material, such as Bakelite or the like, is fixed to an integral ear extending upwardly from the base plate. The Bakelite insulation member also has an integral projection on its lower end which is adapted to be received in a slot formed in the base plate. A rivet is fixed adjacent one end of the insulation member, and this rivet includes an outwardly extending threaded stem which receives a notch or slot formed in the lower side of the spring member near its free outer end. The slot or notch is received over the reduced diameter of an unthreaded part of the rivet, whereby the free end of the spring is arranged in position and initially held in place, later to be fixedly locked in position by locking means on the threaded stem of the rivet member.

The primary object of the present invention is the provision of a new and improved locking means for locking the free end of a spring for the contact arm, whereby the spring is originally arranged in assembled position, and then finally locked fixedly in place.

Another object of the invention consists in the securement of an insulating member to an integral ear extending upwardly from the base plate, an integral projection on the member being engageable with a slot in the base plate, there being a rivet passing through the insulated member and an integral threaded stem on the rivet 0 secure the free end of a spring to the insulating mem- A further object of the invention resides in a new and improved fastening means for securing the contact arm spring to an insulating member which is rigidly fixed and secured to the base plate of a contact assembly, the fastening means mounting the free end of the contact spring removably in position with respect to the insulating member, so as to initially secure the spring in position easily and quickly and maintain the parts in relative posi tion, and then finally lock the parts in place.

Numerous other objects and advantages will be apparent throughout the progress of the specification which follows.

The accompanying drawing illustrates a certain selected embodiment of the invention, and the views thereassssaa Fig. 2 is a detail perspective view of the contact assembly, certain parts being omitted for the sake of clearness;

Fig. 3 is a detail exploded view of the contact assembly of the invention showing various parts for locking the free end of the contact spring to the insulated member on the base plate;

Fig. 4 is a top plan view of the contact assembly of the invention in assembled position; and

Fig. 5 is a detail transverse sectional view'on the line 5--5 of Fig. 4, the view being greatly enlarged for the sake of clearness.

The contact assembly herein disclosed for the purpose of illustrating the invention comprises a conventional type of distributor plate 1 having a rigid post 2 secured thereto, a removable contact assembly unit 3 being mounted on the distributor plate, the post 2 receiving a part of the assembly. The unit contact assembly 3 includes a hollow two-bored ferrule 4 which is secured to the base plate 5 of the contact unit assembly 3.

The assembly 3 includes a contact arm 6 which is applied over the ferrule 4 and is insulated therefrom. The free end of the contact arm 6 is provided with a contact 7 which is adapted to engage a similar contact 8 formed on an integral ear 9 struck up from the base plate 5. A flat contact spring 10 has one end fastened to the contact arm 6 and its other free end 11 provided with a slot 12 at its lower end for fastening the free end 11 of the spring 10 to an insulation member 13. The insulation member 13 is in the form of an elongated thin rectangular block of insulating material, such as Bakelite. One end of the insulation member is riveted as at 14 to an upstanding ear 15 integrally formed with the base plate 5, and a downwardly extending projection is provided on the insulation member which is engaged in a slot formed in the base plate 5. A rubbing block 16 is fixed to the contact arm 6 and is also fixed to one end of the spring 10.

The parts so far described, the manner of assembly, and the manner of securing the various parts together are disclosed in the aforesaid Patent No. 2,727,104.

The present invention resides primarily in the manner in which the free end 11 of the spring lil is secured to the insulated block 13 by means of new and improved holding and securing means 17.

The holding and securing means 17 comprise a stud or rivet 18 which engages a washer-like element 19 fitted against the inner side of the insulating member 13. A collar-like element 20 engages the opposite surfaces of the insulating member 13,- whereby the insulating member is impinged and locked between the collar 20 and the washer member 19 when the rivet member 13 is secured in place to the insulating member 13. The rivet member 18 extends outwardly in the form of a stem 21, part of which has a thread 22. The stem 21 has a part which is reduced in diameter, as indicated at 23, the reduced part 23 extending inwardly of the collar 20 a predetermined distance sufficient to receive the free end 11 of the spring 10 at the slot 12. The slotted free end of the spring 10, therefore, may be slipped over the stem 21, at the reduced diameter 23, to hold the spring 10 in initial assembled position in the manner clearly shown in Fig. 2. Asplit locking ring 24 is slipped over the outer side of the spring 10 by pressing the slit part of its opening 25 over the reduced stem part 23 which is smooth and unthreaded. A flat plate 26, having a top ledge 27, is provided with a hole 28, Fig. 3, which passes through the threaded part of the stem 21. A locking nut 29 threadingly engages the threads 22 on the stem 21. A split lock washer 30 may be inserted between the nut 29 and the plate 26 to hold the nut in position and to prevent the 2; nut from becoming accidentally or inadvertently loosened.

The invention, therefore, provides means for permitting preassembly of the contact spring with respect to the fastening or securing means 17, and then causing final assembly by tightening the nut to lock the free end of the spring tightly in place. The various parts of the assembly 17 may then be easily and quickly applied in position and the spring maintained first in preassembled position, and finally in fixed locked position. The preassembly of inserting the slotted end of the spring over the -reduced part 23 of the stem 21 holds the parts in position without the use of any tools, whereafter the locking ring 24, which is also arranged in the reduced diameter part 23, assists in maintaining the free end of the spring in its preassembled position. Parts may be thus locked in final assembled position by the application of the nut 29. It has been found desirable to apply the member 26 against the split locking ring 24 so that when the split lock washer 30 is arranged in place, and the nut 29 tightened, the parts will be securely held in assembled but locked position. The invention is composed of few and simple parts which may be readily applied in position to lock the parts in assembled relationship.

Changes may be made in the form, construction and arrangement of the parts without departing from the spirit of the invention or sacrificing any of its advantages, and the right is hereby reserved to make all such changes as fall fairly Within the scope of the following claims.

The invention is claimed as follows:

1. A distributor contact assembly comprising a base plate adapted to be mounted on a distributor plate, a contact arm pivotally mounted on said plate, an insulated member fixed to said plate, a spring having its inner end fixed to the contact arm, and means for securing the outer free end of the spring to the insulated member, said last named means comprising a rivet-like member comprising a protruding stem having its outer end threaded, said stem including a smooth part inwardly of said threaded part and of a reduced diameter, collars on said rivetlike member and impinging the insulated member therebetween, the outer free end of said spring having a slot formed therein engagcable with the reduced diameter of the stem to initially hold the spring to the rivet-like member, a split locking ring arranged outwardly of the spring and receivable in the reduced diameter to further hold the spring in position, a plate having an opening receiving the stem, an inturned flange on the plate ex tending over the top of the insulated member and said spring, a nut on the threaded end of the stem for locking the parts in assembled position, said plate and flange preventing shiftable movement of the spring and split member upon tightening of the nut.

2. A distributor contact assembly comprising a base plate adapted to be. mounted on a distributor plate, a contact arm pivotally mounted on said plate, an insulated member fixed to said plate, a spring having its inner end fixed to the contact arm, and means for securing the outer free end of the spring to the insulated member, said last named means comprising a rivet-like member comprising a protruding stem having its outer end threaded, said stem including a smooth part of reduced diameter inwardly of said threaded part, collars on said rivetlike member and impinging the insulated member therebetween, the'outer free end of said spring having a slot engageable with the reduced diameter of the stem to hold the spring in initial position, a split locking ring arranged outwardly of the spring and having parts thereor" projecting toward the reduced diameter, a plate having an opening receiving the stem, an inturned'flange on the plate and extending over'the top of the spring and insulated member, a nut on the threaded end of the stem for locking the parts in assembled position, said plate and flange preventing shiftable movement of the spring and split member upon tightening of the nut, and a lock washer arranged outwardly of said plate and inwardly of said nut to prevent accidental rotative movement of the nut.

References Cited in the file of this patent UNITED STATES PATENTS 1,058,583 Hart Apr. 8, 1913 1,491,394 Grifith et al. Apr. 22, 1924 1,797,766 Frye Mar. 24, 1931 2,246,901 Schwarzmann June 24', 1941 2,328,757 Tinnerman Sept. 7, 1943 2,464,565 Evans etal. Mar. 15, 1949 2,470,927 Hale May 24, 1949 2,639,179 Phelps May 19, 1953 2,727,104 Filko Dec. 13, 1955 2,777,909 Weil- Jan. 15, 1957 

